A conventional rotor of an electric motor described in Patent Literature 1 includes a yoke molded of thermoplastic resin containing soft magnetic material or ferrite, and a resin magnet section integrally formed of a resin magnet in an outer circumference of the yoke. This resin magnet section is molded of a resin magnet supplied from a donut-like runner located inside the yoke and rib-like runners radially extending from the donut-like runner to the outer circumference of the yoke outward in a radial direction. A pedestal on which a magnet for position detection is to be placed is formed on an axial direction end face of the resin magnet section by the resin magnet injected though the rib-like runners.